Cincinnati, OH has a population of 298,011 and is the 65th largest city in the United States. The population density is 3,825 per sq mi which is 1385% higher than the Ohio average and 4122% higher than the national average. The median age in Cincinnati is 32 which is approximately 18% lower than the Ohio average of 39. In Cincinnati, 35% of the population over 15 years of age are married, 92% speak English and 3% speak Spanish. 71% of Cincinnati residents were born in Ohio, 23% were born out of state, 1% were born outside of the United States and 5% were foreign born.